The present disclosure relates to a hydraulic pressure control device of a vehicle driving device to be mounted in, for example, a vehicle.
Conventionally, an automatic transmission capable of forming a plurality of transmission shift stages by engaging and releasing engagement elements such as a plurality of clutches and brakes has been widely used as an automatic transmission having a multi-stage transmission. In addition, hybrid vehicles having an internal combustion engine and a rotary electric machine as driving sources have been widely used and a vehicle driving device having the above automatic transmission is known as a vehicle driving device to be mounted in such hybrid vehicles (JP-A-2013-96422). In this vehicle driving device, by operating a solenoid valve and the like of the hydraulic pressure control device, the forward first stage is achieved by combining a clutch with a brake or combining a clutch with a one-way clutch, and the forward second to fourth stages are achieved by combining two clutches or combining a clutch with a brake. In addition, in the vehicle driving device, the reverse first stage is achieved by forming a transmission shift state using the same combination of a clutch and a brake as in the forward first stage and reversely rotating the electric motor. In the vehicle driving device, when switching to the forward second to fourth stages has been made, since the one-way clutch prevents reverse rotation even if an attempt is made to reverse the electric motor for reverse travel, the reverse second to fourth stages cannot be achieved.